"But you - three or four years ago - probably would never have thought we'd get this far. And we've set ourselves deliberately tough targets so that we really do drive forward policy and have a real change for children and their families".

Labour MP and former social security minister Frank Field said: "The target is audacious but it is not achievable.

'Braver ideas'

"I was amazed and gobsmacked when the government announced it."

Mr Field added that "braver" ideas were needed to alleviate child poverty.

Under the government's welfare-to-work policies, more than 300,000 extra lone mothers have found employment. But campaigners believe these strategies have left behind large families or those with disabled children.

Guy Palmer from the New Policy Institute said he thought the target set was right, calling it "challenging but achievable". The government should "redouble their efforts", he added.

Charity One Parent Families said the government had set itself "a historic and laudable task" to reduce and eventually eliminate child poverty, and serious progress had been made.

Earlier Sir Jeremy Beecham, vice-chairman of the Local Government Association, said there had been a significant reduction in child poverty but there was "still much to be done".

He said enhancing the take-up of council tax benefit by the low paid would help reduce poverty numbers further.